Analysis of the internal structure of a carbonate damage zone: Implications for the mechanisms of fault breccia formation and fluid flow

2010 ◽  
Vol 32 (9) ◽  
pp. 1349-1362 ◽  
Author(s):  
Stefan Hausegger ◽  
Walter Kurz ◽  
Robert Rabitsch ◽  
Eva Kiechl ◽  
Franz-Josef Brosch
Keyword(s):  
Fluid Flow ◽  
Internal Structure ◽  
Damage Zone ◽  
Fault Breccia

scholarly journals The role of pre-existing jointing on damage zone evolution and faulting style of thin competent layers in mechanically stratified sequences: a case study from the Limestone Coal Formation at Spireslack Surface Coal Mine

2020 ◽  
Author(s):  
Billy J. Andrews ◽  
Zoe K. Shipton ◽  
Richard Lord ◽  
Lucy McKay
Keyword(s):  
Fluid Flow ◽  
Internal Structure ◽  
Coal Mine ◽  
Damage Zone ◽  
Fault Rock ◽  
Surface Coal Mine ◽  
Fracture Mapping ◽  
Fault Growth

Abstract. Fault and fracture networks play an important role in sub-surface fluid flow and can act to enhance, retard or compartmentalise groundwater flow. In multi-layered sequences, the internal structure and growth of faults is not only controlled by fault throw, but also the mechanical properties of lithologies cut by the fault. This paper uses geological fieldwork, combined with fault and fracture mapping, to investigate the internal structure and fault development of the mechanically stratified Limestone Coal Formation and surrounding lithologies exposed at Spireslack Surface Coal Mine. We find that the development of fault rock, and complexity of a fault zone is dependent on: a) whether a fault is self-juxtaposed or cuts multiple lithologies; b) the presence and behaviour of shale, which can lead to significant bed-rotation and the formation of fault-core lenses; and c) whether pre-existing weakness (e.g. joints) are present at the time of faulting. Pre-existing joint networks in the McDonald Limestone, and cleats in the McDonald Coal, influenced both fault growth and fluid flow within these lithologies.

Manipulation of toroidal-spiral particles internal structure by fluid flow

2021 ◽  
Vol 33 (5) ◽  
pp. 054102
Author(s):  
Paola A. Leon Plata ◽  
Ludwig C. Nitsche ◽  
Ying Liu
Keyword(s):  
Fluid Flow ◽  
Internal Structure

scholarly journals High-Efficient Micro Reacting Pipe with 3D Internal Structure: Design, Flow Simulation, and Metal Additive Manufacturing

2020 ◽  
Vol 10 (11) ◽  
pp. 3779
Author(s):  
Xiaomin Chen ◽  
Di Wang ◽  
Jingming Mai ◽  
Xiaojun Chen ◽  
Wenhao Dou
Keyword(s):  
Fluid Flow ◽  
Additive Manufacturing ◽  
Internal Structure ◽  
Cfd Simulation ◽  
Structure Design ◽  
Design Flow ◽  
Mixing Efficiency ◽  
Metal Additive Manufacturing ◽  
High Efficient ◽  
Metal Additive

The micro reacting pipe with 3D internal structure, which is a micromixer with the shape of the pipe, has shown great advantages regarding mass transfer and heat transfer. Since the fluid flow is mostly laminar at the micro-scale, which is unfavorable to the diffusion of reactants, it is important to understand the influence of the geometry of the microchannel on the fluid flow for improving the diffusion of the reactants and mixing efficiency. On the other hand, it is a convenient method to manufacture a micro reacting pipe in one piece through metal additive manufacturing without many post-processing processes. In this paper, a basis for the design of a micromixer model was provided by combining the metal additive manufacturing process constraints with computational fluid dynamics (CFD) simulation. The effects of microchannel structures on fluid flow and mixing efficiency were studied by CFD simulation whose results showed that the internal micro-structure had a significantly positive effect on the mixing efficiency. Based on the simulation results, the splitting-collision mechanism was discussed, and several design rules were obtained. Two different materials were selected for manufacturing with the laser powder bed fusion (L-PBF) technology. After applying pressure tests to evaluate the quality of the formed parts and comparing the corrosion-resistance of the two materials, one material was picked out for the industrial application. Additionally, the chemical experiment was conducted to evaluate the accuracy of the simulation. The experimental results showed that the mixing efficiency of the micro reacting pipe increased by 56.6%, and the optimal determining size of the micro reacting pipe was 0.2 mm. The study can be widely used in the design and manufacture of a micromixer, which can improve efficiency and reacting stability in this field.

Fluid flow history from damage zone cements near the Dent and Rawthey faults, NW England

2008 ◽  
Vol 165 (4) ◽  
pp. 829-837 ◽  
Author(s):  
N.H. WOODCOCK ◽  
N.J. SAYERS ◽  
J.A.D. DICKSON
Keyword(s):  
Fluid Flow ◽  
Damage Zone

scholarly journals Internal Structure Characteristics and Formation Mechanism of Reverse Fault in the Carbonate Rock, A Case Study of Outcrops in Xike’er Area, Tarim Basin, Northwest China

2021 ◽  
Vol 9 ◽  
Author(s):  
Feng Geng ◽  
Haixue Wang ◽  
Jianlong Hao ◽  
Pengbo Gao
Keyword(s):  
Internal Structure ◽  
Fresh Water ◽  
Tarim Basin ◽  
Deformation Mechanism ◽  
Carbonate Rock ◽  
Oil And Gas ◽  
Damage Zone ◽  
Northwest China ◽  
Hydrothermal Fluids ◽  
Reverse Fault

China’s Paleozoic deep carbonate effective reservoirs, mainly non-porous reservoirs, are generally formed under the interaction of late diagenesis, hydrothermal fluids, and structural fractures. Faults and their deformation mechanism and internal structure of fault zones play an important role in the formation of carbonate reservoirs and hydrocarbon accumulation. Based on the detailed analysis of outcrop data in Xike’er area, Tarim Basin, this paper systematically studies the deformation mechanism and internal structure of reverse fault in the carbonate rock, and discusses the reservoir characteristics, control factors and development rules. The study shows that the deformation mechanism of the fault in carbonate rocks is faulting and fracturing, and the dual structure of fault core and damage zone is developed. The fault core is mainly composed of fault breccia, fault gouge and calcite zone, and a large number of fractures are formed in the damage zone, which are cemented by calcite locally. The mineral composition and rare earth element tests show that the fault core has the dual effect of hydrothermal fluids and atmospheric fresh water, which is easy to be cemented by calcite; while the damage zone is dominated by atmospheric fresh water, which is a favorable zone for the development of fracture-vuggy reservoirs. Therefore, the damage zone is the “sweet spot” area of carbonate oil and gas enrichment, and generally shows strip distribution along the fault.

scholarly journals Transient conduit permeability controlled by a shift between compactant shear and dilatant rupture at Unzen volcano (Japan)

2021 ◽  
Author(s):  
Yan Lavallée ◽  
Takahiro Miwa ◽  
James D. Ashworth ◽  
Paul A. Wallace ◽  
Jackie E. Kendrick ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Shear Zone ◽  
Damage Zone ◽  
Volcanic Eruptions ◽  
Shear Zones ◽  
Stick Slip ◽  
Anisotropic Permeability ◽  
Unzen Volcano ◽  
Porosity And Permeability ◽  
Low Porosity

Abstract. The permeability of magma in shallow volcanic conduits controls the fluid flow and pore pressure development that regulates gas emissions and the style of volcanic eruptions. The architecture of the permeable porous structure is subject to changes as magma deforms and outgasses during ascent. Here, we present a high-resolution study of the permeability distribution across two conduit shear zones (marginal and central) developed in the dacitic spine that extruded towards the closing stages of the 1991–1995 eruption at Unzen volcano, Japan. The marginal shear zone is approximately 3.2 m wide and exhibits a 2-m wide, moderate shear zone with porosity and permeability similar to the conduit core, transitioning into a ~1-m wide, highly-sheared region with relatively low porosity and permeability, and an outer 20-cm wide cataclastic fault zone. The low porosity, highly-sheared rock further exhibits an anisotropic permeability network with slightly higher permeability along the shear plane (parallel to the conduit margin) and is locally overprinted by oblique dilational Riedel fractures. The central shear zone is defined by a 3-m long by ~9-cm wide fracture ending bluntly and bordered by a 15–40 cm wide damage zone with an increased permeability of ~3 orders of magnitude; directional permeability and resultant anisotropy could not be measured from this exposure. We interpret the permeability and porosity of the marginal shear zone to reflect the evolution of compactional (i.e., ductile) shear during ascent up to the point of rupture, estimated by Umakoshi et al. (2008), at ~500 m depth. At this point the compactional shear zone would have been locally overprinted by brittle rupture, promoting the development of a shear fault and dilational Riedel fractures during repeating phases of increased magma ascent rate, enhancing anisotropic permeability that channels fluid flow into, and along, the conduit margin. In contrast, we interpret the central shear zone as a shallow, late-stage dilational structure, which partially tore the spine core with slight displacement. We explore constraints from monitored seismicity and stick-slip behaviour to evaluate the rheological controls, which accompanied the upward shift from compactional toward dilational shear as magma approached the surface, and discuss their importance in controlling the permeability development of magma evolving from overall ductile to increasingly brittle behaviour during ascent and eruption.

scholarly journals Clay minerals from the Arkitsa fault gouge zone, in Central Greece, and implications for fluid flow

2017 ◽  
Vol 47 (2) ◽  
pp. 616 ◽  
Author(s):  
D. Papoulis ◽  
D. Romiou ◽  
S. Kokkalas ◽  
P. Lampropoulou
Keyword(s):  
Fluid Flow ◽  
Clay Minerals ◽  
Fault Zone ◽  
Damage Zone ◽  
Fault Gouge ◽  
Hydrothermal Conditions ◽  
Core Zone ◽  
Damage Area ◽  
Central Greece ◽  
Alkaline Conditions

Clay minerals in shallow fault rocks are increasingly recognized as key to the mechanical and seismogenic behavior of faults and fluid flow circulation within the fault core and the surrounding damage zone. We therefore studied faultgouge mineralogy from samples derived from the ENE-trending Arkitsa fault zone, in east-central Greece, in order to testify if the fault is acting as a channel for fluid flow and whether the conditions that characterize the flow can be identified. Clay-gouge samples were collected within the fault core zone, as well as in the broader fault damage area. Consequently, the samples were analyzed by X-Ray Diffraction, SEM and Electron microprobe analyses. The minerals that were identified within the centre of the fault zone are: Montmorillonite, corrensite, illite, micro-calcite, dolomite, quartz, plagioclase and K-feldspars. The absence of corrensite, a clay mineral usually formed in hydrothermal conditions, in the samples from the broader fault damage area indicates that the circulation of hydrothermal fluids is mostly confined within and around the fault core zone. The assemblages within the fault gouge zone and especially the presence of corrensite, combined with the absence of laumontite, indicate hydrothermal alteration at neutral to alkaline conditions and a temperature range at about 100-150 oC.

Dating faults, fractures and fluids with U-Pb calcite geochronology: Application to contrasting fracture and fluid-flow modes of the Cleveland Basin

2020 ◽  
Author(s):  
Jack Lee ◽  
Nick Roberts ◽  
Robert Holdworth ◽  
Andrew Aplin ◽  
Richard Haslam ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Fault Zone ◽  
Failure Modes ◽  
Damage Zone ◽  
Source Rocks ◽  
Normal Faults ◽  
Fluid Composition ◽  
Natural Fractures ◽  
Seal Integrity ◽  
Clumped Isotope

<p>Fractures and faults act as important permeable pathways in the subsurface and are of great significance to the petroleum industry and for future Carbon Capture and Storage. Fractures allow fluid-flow through impermeable units such as mudrocks and can affect how these lithologies act as top seals, source rocks and/or unconventional reservoirs. Natural fractures within mudrocks can strongly influence top seal integrity, primary migration and the performance of unconventional (e.g. shale gas) reservoirs. This project studies the exhumed, early-mature, Jurassic mudrock succession of the Cleveland Basin, NE England, combining structural geology with isotope geochemistry and geochronology. The primary objective is to provide an absolute chronology of faulting and fracturing through novel U-Pb geochronology of fracture-fill calcite. The abundance of well-exposed, natural fractures with different orientations and failure modes provides an opportunity to investigate the properties of these fractures, and provide a basin-wide temporal and spatial framework of evolving deformation. The second objective is to use trace element, stable isotope, and clumped isotope analyses, to constrain fluid composition and temperature. In combination, these objectives will provide an integrated understanding of fracturing, faulting and fluid migration during burial and exhumation of a sedimentary basin.</p><p>Current fracture-fill dates from U-Pb geochronology provide intriguing insights into the history of the Cleveland Basin. We have identified and dated three phases of deformation and associated fluid-flow that have contrasting kinematics and fluid-flow regimes. The E-W trending Flamborough Head Fault Zone (FHFZ) bounds the basin to the south, and calcite preserved in one of the major extensional faults provides ages of 64-56 Ma. Calcite from N-S to NNW-SSE trending normal faults and associated fractures in the north of the Cleveland Basin provide ages of 44-25 Ma, revealing a previously unknown phase of Cenozoic faulting, which we speculatively relate to salt-related deformation. Structural and petrographic information suggest that the E-W and N-S trending faults have contrasting fracture-fluid-flow systems. Large (up to 30 cm), chalk hosted, vuggy calcite cements with geopetal sediment-fills in the E-W fault zone suggest it acted as an open fluid conduit with voluminous fluid-flow, linking the shallow sub-surface with deeper levels of the stratigraphy. In contrast, typically thin (<5 mm) vein fills with varying crack-seal-slip type textures in the N-S mudstone-hosted fractures of the Cleveland Basin provide evidence of episodic slip of variable displacement (44-40 Ma); these fracture openings may partly be controlled by pore fluid pressures and pre-date fault movement along the regional Peak Fault and smaller scales N-S faults (40-25 Ma) which are characterised by damage zone calcite mineralisation and extensional jog structures. Initial stable isotopic results are giving indications of fluid temperatures and sourcing which will be built on further by clumped isotope and fluid inclusions work.</p>

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